public async Task DeleteQualificationAsync(Project source, int qualificationId)
        {
            ProjectQualification projectQualification = await GetDbProjectQualification(source.Id, qualificationId);

            _context.ProjectQualifications.Remove(projectQualification);
            await _context.SaveChangesAsync();
        }
        public async Task AddQualificationsAsync(Project source, IEnumerable <int> qualificationsToAddIds)
        {
            foreach (int qualificationId in qualificationsToAddIds)
            {
                ProjectQualification projectQualification = new ProjectQualification {
                    ProjectId = source.Id, QualificationId = qualificationId
                };
                await _context.ProjectQualifications.AddAsync(projectQualification);
            }

            await _context.SaveChangesAsync();
        }